Dear Mr. Thomas Curiano,
Thank you for posting your request on History Hub! However, we do not have enough information from your request to move forward. We can suggest some of the following guides to assist in your research. https://www.archives.gov/research/genealogy/catalog-guide
You can enter your Grandfather's name in the search box at https://catalog.archives.gov/ but it is also possible that you may want to use Ancestry.com (a fee based web site) to locate the records you seek or Familysearh.org (requires a login and password but free to use).
Finally, if you know the court in which your Grandfather's name was changed, you may want to contact the court to seek the information you require. For a listing of Federal Courts, you can use https://www.fjc.gov/history/courts. The court should be able to provide you with the information necessary to locate the Name Change Petition you seek.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from Textual Reference (RDT2). We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!
Leo L. Belleville III,